The present invention generally relates to anodes being utilized in cathodic protection system of underground or submerged pipelines, reservoirs and structures.
Internal and external, underground and submerged metallic surfaces of pipelines, reservoirs and other structures are subject to corrosion due to electrochemical reactions between the metallic surfaces and the corrosive medium they are in contact with. Cathodic protection systems are installed in pipelines, reservoirs and other structures to limit the amount of corrosion occurring on the subjected surfaces. Pipeline operators and Tank & facility owners use either impressed current and/or galvanic cathodic protection systems that both imply a series of anodes in order to mitigate and control the severity of corrosion attacks.
Known anode materials used in cathodic protection systems are high silicon cast iron, magnesium, zinc, and aluminum alloys. These anodes are produced using casting techniques in different sizes and shapes depending on application and are commonly produced in the shape of simple rod, tube, and rectangular cube using sand molded casting or metal die casting techniques.
Current output capacity or efficiency of each cathodic protection anode in a specific medium is limited by the surface area of anode which is in contact with the medium. On the other hand, the weight of anode is a very important factor in casting industry from a cost-efficiency point of view. Increasing the anode weight to achieve larger surface area would dramatically increase casting, handling, shipping and installation costs.